Dado and gain saws



June I, 1943. R WEDDLE ET L 2,320,539

DADO AND GAIN SAW Original Filed Feb. 21, 1940 2 Sheets-Sheet l M J; WMeyerg J1? hffiddie June 1, 1943.

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J. P WEDDLE ET DADO AND GAIN SAW 2 Sheets-Sheet 2 ginal Filed Feb. 21, 1940 Patented June 1, 1943 UNETED STATES FA'EENT ()FFICE Okl Original application February 21, 1940, Serial No.

320,214. Divided and this application February 6, 1941, Serial No. 377,743

(Cl. 1453l) 5 Claims.

This invention relates to an improved construction of saw for use in cutting dadoes and gains and constitutes a division of our co-pending application, Serial No. 320,214, filed February 21, 1940, which has matured into Patent No. 2,281,469 and entitled Dado, gain and miter saws.

More particularly, it is an aim of this invention to provide an improved construction of saw by means of which carpenters will be enabled to quickly and easily cut neat dadoes and gains in one operation and particularly adapted for dadoing window and door jambs, shelf ends and uprights, for gaining door fronts, sides and backs; and which is further designed for use with cheap grades of lumber containing knots and which would otherwise not be adaptable for work requiring grooves, notches and mortises.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, which illustrate a preferred embodiment thereof, and wherein:

Figure l. is a side elevational view of a dado and gain saw constructed in accordance with the invention,

Figure 2 is a similar view looking toward the opposite side of the same,

Figure 3 is a longitudinal, substantially central vertical sectional view, partly in side elevation of the saw,

Figure 4 an enlarged longitudinal horizontal sectional View taken substantially along the plane of the line 4- 3 of Figure 3,

Figures 5 and 6 are transverse sectional views taken substantially along the planes of the lines 5-5 and ii 5, respectively, of Figure 3,

Figure 7 is an enlarged transverse sectional view taken substantially along the plane of the line -"l of Figure 1,

Figure 8 is a plan view of the cutting bit, and

Figure 9 is a similar view of the gouge.

Referring more particularly to the drawings, wherein like reference characters designate like or corresponding parts throughout the different views, 50 designates generally a saw constructed in accordance with the invention and including an elongated head or holding frame ll having an upwar ly inwardly inclined end !2 and an elongated slot i3 disp-"sed adjacent said end and substantially parallel thereto to receive the fingers of operator and to form with said end 52 the handle portion of the saw. The head or frame it is provided with a longitudinally disposed slot M intermediate of its ends and adjacent its upper edge.

A pair of corresponding saw blades l5 are mounted on the head or frame ll, one on each side thereof, and are adjustably connected thereto by means of a plurality of nut and bolt fastenings l5 which extend through transversely disposed openings ll in the head or frame I I, adjacent the lower edge thereof, and through alined transversely disposed slots l8 in the saw blades it. as best seen in Figures 1, 2, 6 and 7. The slots i8 open outwardly of the upper edges of the saw blades l5 and combine with the fastenings Hi to provide means whereby the blades I5 may be readily attached to or detached from the frame H and adjusted perpendicularly thereof and of one another. The depending, lower edges of the saw blades 55 are provided with saw teeth I 9, and as best seen in Figures 3 and 5, the toothed edges is disposed substantially below the bottom edge of the frame H and the blades I5 are adapted to be adjustably secured to the frame H by the fastenings It so that the toothed edges i9 will be disposed in the same horizontal plane for cutting spaced kerfs in a piece of material to substantially the same depth.

Referring particularly to Figures 2 and 7, a gage plate 20 is provided with transverse slots 2|, which open outwardly of the upper edge thereof and which are adapted to aline with the slots I8 of the blades 15 which are disposed intermediate of the ends of the blades for receiving the fatenings it thereof and by means of which the gage plate 20 is adjustably secured to the frame H on one side thereof and is adapted to be ad justed perpendicularly of the saw Ill. The lower edge of the gage plate 29 is adapted to be positioned above the level of the toothed edges IE) to limit the cutting depth of the saw blades, as will be readily apparent. As best seen in Figure 7, the bolts of the fastenings l6 which engage the slots 2i are also provided with spacing nuts 22 which are disposed between the plate 20 and the saw blade l5, which is adjacent thereto, and which retain the plate 20 in spaced apart, substantially parallel relationship to said aforemen lever 23 extends rearwardly relatively to the.

blades l5 and is provided with a downturned free end 26 which is provided with a set screw 21 and a guide pin 28 which projects from the outer, rear side of the downturned end 23. Referring to Figure 9, 29 designates a gouge bit having a sharpened toothed end 30 and a longi tudinal slot 3| which opens outwardly of the opposite end thereof and which is adapted to be engaged by the guide pin 28 and the shank of the set screw 21 and which is adapted to provide means in combination with the set screw 21 for adjustably and detachably fastening the gouge bit 29 to the depending end 26 of the lever 23 so that the cutting end 30 thereof will depend downwardly therefrom below the lower end of the end portion 26 and will be disposed between the toothed edges i9. Th frame II is provided with a recess 32 in its under side and with a bore 33, one end of which opens into the recess 32 and the opposite end of which opens into the slot I4, adjacent the forward end thereof. A rod or bolt 34 is provided with an eyelet 35 at its lower end, as best seen in Figure 3, which is disposed in a recess 36 in the upper side of the lever 23 and adjacent its free end, and which is pivotally connected thereto by means of a pin 31 which extends therethrough. The rod 34 extends upwardly through and is loosely mounted in the bore 33 and is provided with a threaded opposite end which is disposed in the opening formed by the slot I4 and to which is adjustably connected a wing nut 38 which is adjustable for limiting the extent of the downward movement of the rod 34 relatively to the frame II. An expansion coil sprin 39 is mounted on the lower end of the rod 34 and has one end bearing against the lever 23 and its opposite end seated in the recess 32 for normally urging the free end of the lever 23 and the gouge bit 29 downwardly. It will thus be seen that the spring 39 urges the gouge bit 29 downwardly and that the wing nut 38 can be adjusted for varying the downward movement of the bit 29 and to thereby provide means in conjunction with the spring 39 for varying the elevation of the bit 29 relatively to the toothed edges I 9.

A bolt and nut fastening 40 extends through and is mounted in the blades |5 adjacent their rear ends and beneath and adjacent the frame I I. A lever 4| is provided with an opening 42 adjacent one end thereof for loosely engaging the shank of the bolt of the fastening 40 for pivotally mounting the lever 4| between the blades I5. The lever 4|, as best seen in Figure 3, extends forwardly and downwardly relatively to the blades l5 and is provided with a free end which i is beveled at 43 on its under side. A screw 44 is mounted in the lever 4|, adjacent its free end, and extends upwardly therefrom and is provided with a nut 45. Referring to Figure 8, 46 designates generally a cutting bit, the under side of one end of which is beveled to form a cutting edge 41. The cutting bit 46 is provided with a longitudinal slot 48 adjacent its opposite end which is adapted to engage the shank of the screw 44 for adjustably positioning the bit relatively to the free end of the lever 4|. The nut 45 is adapted to be tightened to clamp the bit 46 in adjusted position relatively to the lever 4|. The frame I I is provided with a notch which opens into the slot I4, at the bottom thereof, and adjacent its rear end and which forms an inclined surface 49, and said frame is also provided with a notch in its bottom edge forming an inclined surface 50. The surfaces 49 and 59 are disposed substantially parallel to one another and to the lever 4| when said lever is in its normal, downwardly inclined position, as seen in Figure 3. The frame H is provided with a rela tively large bore 5|, one end of which opens into the surface 49 and the opposite end of which opens into the surface 50 and which is disposed substantially at right angles to said surfaces. A rod or bolt 52 is fixed at one end in the lever 4|, intermediate of the ends thereof, and projects upwardly therefrom through the bore 5| and is provided with a threaded upper end to receive a wing nut 53 which is disposed in the slot I4 and which bears against the surface 49. An expansion coil spring 54 is mounted on the lower end of the rod 52 and has one end thereof bearing against the lever 4| and its opposite end bearing against the surface 50 for normally urging the lever 4| downwardly. It will be obvious that the wing nut 53 can be adjusted for raising and lowering the lever 4| and combines with the spring 54 for yieldably and adjustably positioning the lever 4| and the bit 45, carried thereby, relatively to the toothed edges l9. As best seen in Figure 3, the bore 5| is of a diameter substantially greater than the rod '52 to permit the rod 52 to swing relatively to the bore 5| as the lever 4| is raised and lowered.

Assuming the parts of the saw ID to be assembled and adjusted to the positions, as illustrated in the drawings and as previously described, the saw I!) can be usedfor forming a gain or dado in a piece of material, not shown, and the spaced toothed edges I9 of the blades I5 will cut two spaced, substantially parallel kerfs in the material. At the same time, the toothed cutting edge of the gouge bit 29, which is of substantially the same width as the space between the blades l5, as seen in Figure 5, will clear the material between the kerfs being made by the cutting edges I9 on the forward stroke of the saw and will also function sufhciently for cutting through knotty portions of the material. The cutting bit 46, which is of substantially the same width as the gouge bit 29, is disposed therebehind for cleaning the dado or gain on the forward stroke of the saw I0 to provide a smooth bed in the groove thus formed and to combine with the gouge bit 29 to insure that the groove will be cut to the same depth throughout its length and width. The levers 23 and 4| are yieldably mounted so that the bits 29 and 49, respectively, can yield upwardly should they strike an obstruction through which they are not able to cut to thereby prevent breakage or damage to either of these parts. The gage plate 29 can be adjusted to limit the cutting depth of the saw H) to any required depth desired.

The saw I0 is also adapted to be used with its gage plate 20 in conjunction with the work holding frame as fully set forth in our co-pending application, heretofore referred to.

Various modifications and changes are contemplated and may obviously be resorted to as only a preferred embodiment of the invention has been disclosed.

We claim as our invention:

1. A dado saw comprising an elongated frame, saw blades arranged one on each side thereof, said saw blades having depending, cutting edges disposed beneath the lower edge of the frame, levers each pivotally connected to the saw blades at an end thereof and disposed therebetween below said frame, a gouging bit detachably and adustabiy connected to one of said levers, a cutting bit detachably and adjustably connected to the other of said levers and disposed behind the gouging bit, and means connecting said levers to the saw frame and provided with spring means in conjunction therewith for adjustably and yieldably mounting the gouging bit and cutting bit between and adjacent the cutting edges of the saw blades.

2. A device of the class described comprising an elongated frame, blades attached to opposite sides thereof and depending below the same, a lever below said frame and between the blades, means mounted between said blades and pivotally mounting the lever, cutter means carried by the lever, and means suspending said lever from the frame.

3. A device of the class described comprising an elongated frame having an opening therethrough, blades attached to opposite sides of the frame and depending below the frame, a lever disposed between the blades and below the frame, means between the blades pivotally mounting said lever, means adjustably suspending said lever, said means slidably mounted in the frame and extending into said opening to enable adjustment through the latter.

4. A device of the class described comprising an elongated frame having an opening, blades secured to opposite sides of the frame and depending below the frame, a lever below the frame and between said blades, cutter means carried by the lever, means mounted between the blades and pivotally mounting said lever, a rod extending from the lever slidably through the frame, an adjusting nut threaded on the rod and accessible through said opening, resilient means surrounding the rod bearing against the lever and against the frame.

5. A device of the class described comprising an elongated frame provided with an opening, blades secured to opposite sides of said frame and depending below the frame, levers below said frame and between said blades, means between the blades pivoting said levers thereto adjacent opposite ends of the blades, a gouging bit carried by one of the levers, a. cutting bit carried by the other lever, rods extending from said levers slidably into the frame, screws threaded on said rod bearing against the frame and operable through said opening, and spring means surrounding the rods bearing against the levers and against the frame.

JOHN P. WEDDLE, JOE W. MEYERS. 

